Homework Help is Here – Start Your Trial Now!
Science
Biology
The figure below depicts the mechanism of iron homeostasis in mammalian cells, in which ferritin is produced to sequester excess iron in high iron conditions, and transferrin receptor is produced to import iron in low iron concentrations. (a) Ferritin mRNA 5 IRE Inactive IRE-BP 5 Active IRE-BP ? High iron Coding region An H₂N COOH Translated ferritin (b) TfR mRNA High iron 5' Coding region Inactive IRE-BP Active IRE-BP Low iron Low iron Coding region A No translation 5' Coding region initiation IRES A ????? a) A mutation in a mammalian cell line in tissue culture was found that constitutively expresses Ferritin. Suggest a possible mutation that could account for this. Degraded mono- nucleotides A Little degradation -Mutation in ires binding protein where it does not bind to iron suggests that cell lysate has high transferrin and low ferritin. I b) Upon further examination of the cell line, it was found that there was normal expression of the Transferrin Receptor. Would the mutation you suggested in part a) be consistent with this finding? Explain why. If the mutation you suggested in part a) is inconsistent, then what alternate mutation in part a) would be consistent with this finding? c) This mutant was found to be barely viable in medium containing a low concentration of iron. Suggest a reason why. Would the mutant be viable in medium with no added iron for a day? Explain. d) A second site partial revertant is found that causes the Transferrin Receptor to now also be constitutively expressed, in addition to the constitutive expression of Ferritin. What kind of second site mutation could account for this phenotype. Explain.

The figure below depicts the mechanism of iron homeostasis in mammalian cells, in which ferritin is produced to sequester excess iron in high iron conditions, and transferrin receptor is produced to import iron in low iron concentrations. (a) Ferritin mRNA 5 IRE Inactive IRE-BP 5 Active IRE-BP ? High iron Coding region An H₂N COOH Translated ferritin (b) TfR mRNA High iron 5' Coding region Inactive IRE-BP Active IRE-BP Low iron Low iron Coding region A No translation 5' Coding region initiation IRES A ????? a) A mutation in a mammalian cell line in tissue culture was found that constitutively expresses Ferritin. Suggest a possible mutation that could account for this. Degraded mono- nucleotides A Little degradation -Mutation in ires binding protein where it does not bind to iron suggests that cell lysate has high transferrin and low ferritin. I b) Upon further examination of the cell line, it was found that there was normal expression of the Transferrin Receptor. Would the mutation you suggested in part a) be consistent with this finding? Explain why. If the mutation you suggested in part a) is inconsistent, then what alternate mutation in part a) would be consistent with this finding? c) This mutant was found to be barely viable in medium containing a low concentration of iron. Suggest a reason why. Would the mutant be viable in medium with no added iron for a day? Explain. d) A second site partial revertant is found that causes the Transferrin Receptor to now also be constitutively expressed, in addition to the constitutive expression of Ferritin. What kind of second site mutation could account for this phenotype. Explain.

Human Heredity: Principles and Issues (MindTap Course List)
Human Heredity: Principles and Issues (MindTap Course List)
11th Edition
ISBN:9781305251052
Author:Michael Cummings
Publisher:Michael Cummings
Chapter9: Gene Expression And Gene Regulation
Section: Chapter Questions
Problem 18QP: The following is a portion of a protein: met-trp-tyr-arg-gly-pro-thr-Various mutant forms of this...
See similar textbooks
icon
Related questions
Topic Video
Question
The figure below depicts the mechanism of iron homeostasis in mammalian cells, in which ferritin is produced to sequester excess iron in high iron conditions, and transferrin receptor is produced to import iron in low iron concentrations. (a) Ferritin mRNA 5% IRE i 5% Inactive IRE-BP Active IRE-BP High iron Coding region - An 85 H₂N COOH Translated ferritin Low iron Coding region A No translation initiation (b) TfR mRNA High iron 5'- Coding region Inactive IRE-BP Active IRE-BP Low iron 5'- Coding region IRES An N a) A mutation in a mammalian cell line in tissue culture was found that constitutively expresses Ferritin. Suggest a possible mutation that could account for this. Degraded mono- nucleotides degradation -Mutation in ires binding protein where it does not bind to iron suggests that cell lysate has high transferrin and low ferritin. I b) Upon further examination of the cell line, it was found that there was normal expression of the Transferrin Receptor. Would the mutation you suggested in part a) be consistent with this finding? Explain why. If the mutation you suggested in part a) is inconsistent, then what alternate mutation in part a) would be consistent with this finding? c) This mutant was found to be barely viable in medium containing a low concentration of iron. Suggest a reason why. Would the mutant be viable in medium with no added iron for a day? Explain. d) A second site partial revertant is found that causes the Transferrin Receptor to now also be constitutively expressed, in addition to the constitutive expression of Ferritin. What kind of second site mutation could account for this phenotype. Explain.
Transcribed Image Text:The figure below depicts the mechanism of iron homeostasis in mammalian cells, in which ferritin is produced to sequester excess iron in high iron conditions, and transferrin receptor is produced to import iron in low iron concentrations. (a) Ferritin mRNA 5% IRE i 5% Inactive IRE-BP Active IRE-BP High iron Coding region - An 85 H₂N COOH Translated ferritin Low iron Coding region A No translation initiation (b) TfR mRNA High iron 5'- Coding region Inactive IRE-BP Active IRE-BP Low iron 5'- Coding region IRES An N a) A mutation in a mammalian cell line in tissue culture was found that constitutively expresses Ferritin. Suggest a possible mutation that could account for this. Degraded mono- nucleotides degradation -Mutation in ires binding protein where it does not bind to iron suggests that cell lysate has high transferrin and low ferritin. I b) Upon further examination of the cell line, it was found that there was normal expression of the Transferrin Receptor. Would the mutation you suggested in part a) be consistent with this finding? Explain why. If the mutation you suggested in part a) is inconsistent, then what alternate mutation in part a) would be consistent with this finding? c) This mutant was found to be barely viable in medium containing a low concentration of iron. Suggest a reason why. Would the mutant be viable in medium with no added iron for a day? Explain. d) A second site partial revertant is found that causes the Transferrin Receptor to now also be constitutively expressed, in addition to the constitutive expression of Ferritin. What kind of second site mutation could account for this phenotype. Explain.
Expert Solution
steps

Step by step

Solved in 2 steps

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Gene expression
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Human Heredity: Principles and Issues (MindTap Co…
Human Heredity: Principles and Issues (MindTap Co…
Biology
ISBN:
9781305251052
Author:
Michael Cummings
Publisher:
Cengage Learning
SEE MORE TEXTBOOKS